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Usher Syndromes
Usher syndrome, also known as Hallgren syndrome, Usher–Hallgren syndrome, retinitis pigmentosa–dysacusis syndrome or dystrophia retinae dysacusis syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes resulting in a combination of hearing loss and visual impairment. It is the most common cause of deafblindness and is at present incurable. Usher syndrome is classed into three subtypes (I, II, and III) according to the genes responsible and the onset of deafness. All three subtypes are caused by mutations in genes involved in the function of the inner ear and retina. These mutations are inherited in an autosomal recessive pattern. The occurrence of Usher syndrome varies across the world and across the different syndrome types, with rates as high as 1 in 12,500 in Germany to as low as 1 in 28,000 in Norway. Type I is most common in Ashkenazi Jewish and Acadian populations, and type III is rarely found outside Ashkenazi Jewish and Finnish popu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having Heterozygosity, two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or Heredity, inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCDH15
Protocadherin-15 is a protein that in humans is encoded by the ''PCDH15'' gene. Function This gene is a member of the cadherin superfamily. Family members encode integral membrane proteins that mediate calcium-dependent cell-cell adhesion. The protein product of this gene consists of a signal peptide, 11 extracellular calcium-binding domains, a transmembrane domain and a unique cytoplasmic domain. It plays an essential role in maintenance of normal retinal and cochlea The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Cort ...r function. It is thought to interact with CDH23 to form tip-link filaments. Clinical significance Mutations in this gene have been associated with hearing loss, which is consistent with its location at the Usher syndrome type 1F (USH1F) critical region on ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birmingham, UK
Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands, within the wider West Midlands region, in England. It is the largest local authority district in England by population and the second-largest city in Britain – commonly referred to as the second city of the United Kingdom – with a population of million people in the city proper in . Birmingham borders the Black Country to its west and, together with the city of Wolverhampton and towns including Dudley and Solihull, forms the West Midlands conurbation. The royal town of Sutton Coldfield is incorporated within the city limits to the northeast. The urban area has a population of 2.65million. Located in the West Midlands region of England, Birmingham is considered to be the social, cultural, financial and commercial centre of the Midlands. It is just west of the traditional centre point of England at Meriden, and is the most inland major city in the country, lying north of the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finns
Finns or Finnish people (, ) are a Baltic Finns, Baltic Finnic ethnic group native to Finland. Finns are traditionally divided into smaller regional groups that span several countries adjacent to Finland, both those who are native to these countries as well as those who have resettled. Some of these may be classified as separate ethnic groups, rather than subgroups of Finns. These include the Kvens and Forest Finns in Norway, the Tornedalians in Sweden, and the Ingrian Finns in Russia. Finnish language, Finnish, the language spoken by Finns, is closely related to other Balto-Finnic languages such as Estonian language, Estonian and Karelian language, Karelian. The Finnic languages are a subgroup of the larger Uralic languages, Uralic family of languages, which also includes Hungarian language, Hungarian. These languages are markedly different from most other languages spoken in Europe, which belong to the Indo-European languages, Indo-European family of languages. Native Finns c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CLRN1
Clarin-1 is a protein that in humans is encoded by the ''CLRN1'' gene. Function This gene encodes a protein that contains a cytosolic N-terminus, multiple helical transmembrane domains, and an endoplasmic reticulum membrane retention signal, TKGH, in the C-terminus. The encoded protein may be important in development and homeostasis of the inner ear and retina. Mutations within this gene have been associated with Usher syndrome Usher syndrome, also known as Hallgren syndrome, Usher–Hallgren syndrome, retinitis pigmentosa–dysacusis syndrome or dystrophia retinae dysacusis syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes result ... type IIIa. Multiple transcript variants encoding distinct isoforms have been identified for this gene. References Further reading * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Retinitis Pigmentosa Overview * {{gene-3-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DFNB31
Whirlin is a protein that in humans is encoded by the ''DFNB31'' gene. In rat brain, WHRN interacts with a calmodulin-dependent serine kinase, CASK A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids ..., and may be involved in the formation of scaffolding protein complexes that facilitate synaptic transmission in the central nervous system (CNS). Mutations in this gene, also known as WHRN, cause autosomal recessive deafness. References Further reading * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Usher Syndrome Type II {{PDB Gallery, geneid=25861 Genes mutated in mice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPR98
ADGRV1, also known as G protein-coupled receptor 98 (GPR98) or Very Large G-protein coupled receptor 1 (VLGR1), is a protein that in humans is encoded by the ''GPR98'' gene. Several alternatively spliced transcripts have been described. The adhesion GPCR VLGR1 is the largest GPCR known, with a size of 6300 amino acids and consisting of 90 exons. There are 8 splice variants of VlgR1, named VlgR1a-1e and Mass1.1-1.3. The N-terminus consists of 5800 amino acids containing 35 Calx-beta domains, one pentraxin domain, and one epilepsy associated repeat. Mutations of VlgR1 have been shown to result in Usher's syndrome. Knockouts of Vlgr1 in mice have been shown to phenocopy Usher's syndrome and lead to audiogenic seizures. Function This gene encodes a member of the adhesion-GPCR family of receptors. The protein binds calcium and is expressed in the central nervous system. It is also known as ''very large G-protein coupled receptor 1'' because it is 6300 residues long. It contain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USH2A
Usherin is a protein that in humans is encoded by the ''USH2A'' gene. This gene encodes the protein Usherin that contains laminin EGF motifs, a pentraxin domain, and many fibronectin type III motifs. The encoded basement membrane The basement membrane, also known as base membrane, is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tis ...-associated protein may be important in development and homeostasis of the inner ear and retina. Mutations within this gene have been associated with Usher syndrome type IIa. Alternatively spliced transcript variants that encode different isoforms have been described. References Further reading * * * * * * * * * * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Usher Syndrome Type II {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard-of-hearing
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken language, and in adults it can create difficulties with social interaction and at work. Hearing loss can be temporary or permanent. Hearing loss related to age usually affects both ears and is due to cochlear hair cell loss. In some people, particularly older people, hearing loss can result in loneliness. Hearing loss may be caused by a number of factors, including: genetics, ageing, exposure to noise, some infections, birth complications, trauma to the ear, and certain medications or toxins. A common condition that results in hearing loss is chronic ear infections. Certain infections during pregnancy, such as cytomegalovirus, syphilis and rubella, may also cause hearing loss in the child. Hearing loss is diagnosed when hearing testi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashkenazi Jewish
Ashkenazi Jews ( ; also known as Ashkenazic Jews or Ashkenazim) form a distinct subgroup of the Jewish diaspora, that Ethnogenesis, emerged in the Holy Roman Empire around the end of the first millennium Common era, CE. They traditionally speak Yiddish, a language that originated in the 9th century, and largely migrated towards Northern Europe#UN geoscheme classification, northern and eastern Europe during the late Middle Ages due to Antisemitism in Europe, persecution. Hebrew was primarily used as a Literary language, literary and sacred language until its 20th-century Revival of the Hebrew language, revival as a common language in Israel. Ashkenazim adapted their traditions to Europe and underwent a transformation in their interpretation of Judaism. In the late 18th and 19th centuries, Jews who remained in or returned to historical German lands experienced a cultural reorientation. Under the influence of the Haskalah and the struggle for emancipation, as well as the intellec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinitis Pigmentosa
Retinitis pigmentosa (RP) is a member of a group of genetic disorders called inherited retinal dystrophy (IRD) that cause loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision (side and upper or lower visual field). As peripheral vision worsens, people may experience " tunnel vision". Complete blindness is uncommon. Onset of symptoms is generally gradual and often begins in childhood. Retinitis pigmentosa is generally inherited from one or both parents. It is caused by genetic variants in nearly 100 genes. The underlying mechanism involves the progressive loss of rod photoreceptor cells that line the retina of the eyeball. The rod cells secrete a neuroprotective substance (rod-derived cone viability factor, RdCVF) that protects the cone cells from apoptosis. When these rod cells die, this substance is no longer provided. This is generally followed by the loss of cone photoreceptor cells. Diagnosis is through eye examination of the retina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinal Pigmented Epithelium
The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells, and is firmly attached to the underlying choroid and overlying retinal visual cells. History The RPE was known in the 18th and 19th centuries as the pigmentum nigrum, referring to the observation that the RPE is dark (black in many animals, brown in humans); and as the tapetum nigrum, referring to the observation that in animals with a tapetum lucidum, in the region of the tapetum lucidum the RPE is not pigmented. Anatomy The RPE is composed of a single layer of hexagonal cells that are densely packed with pigment granules. When viewed from the outer surface, these cells are smooth and hexagonal in shape. When seen in section, each cell consists of an outer non-pigmented part containing a large oval nucleus and an inner pigmented portion which extends as a series of straight thread-like processes between the rods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
